Ruthenium catalyzed ammonia borane (AB) hydrolysis using aqueous solutions in the range of 5-25 wt% were experimentally studied. The experimental apparatus also included a means for gaseous ammonia sequestration. In addition, the effects of aging on reaction rates and total H(2) conversion were investigated using AB solutions that were stored in a limited-air environment for a maximum of 67 days. The present work provides data on total H(2) conversion, chemical kinetics, solution density, pH value, byproduct solubility, ammonia generation, and long-term storage stability of concentrated aqueous AB solutions. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.